Manufacturing method of sensor chip package structure

ABSTRACT

A manufacturing method of a sensor chip package structure is provided. In the manufacturing method, a wafer including a plurality of sensor chips is provided, and each sensor chip has an active region and defines a pre-thinned region thereon. Each pre-thinned region is located at one side of the active region and covers a boundary line of each sensor chip. The pre-thinned region of each sensor chip is etched to form a concave portion. A redistribution layer is formed on the wafer. Subsequently, the wafer is cut to separate the sensor chips from one another, and each separated sensor chip has a wiring layer extending from the active region along a sidewall surface to a bottom surface of the concave portion. The separated sensor chips are respectively mounted on a plurality of substrates, and the active region is electrically connected to the substrate through the wiring layer.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 15/646,533 filed on Jul. 11, 2017 and entitled “OPTICAL SENSORMODULE AND SENSOR CHIP THEREOF”, which is a continuation-in-part of U.S.application Ser. No. 15/096,601, filed on Apr. 12, 2016, now U.S. Pat.No. 9,741,875, and entitled “SENSOR CHIP PACKAGE STRUCTURE ANDMANUFACTURING METHOD THEREOF”, the entire disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The instant disclosure relates to a sensor chip package structure andthe manufacturing method thereof; in particular, to a sensor chippackage structure having an exposed active region and the manufacturingmethod thereof.

2. Description of Related Art

Currently optical sensor package module includes a substrate, a chip,and a molding compound. The chip is disposed on the substrate andelectrically connected thereto, and the molding compound encapsulatesthe substrate and the chip to fix and protect the chip and the wires. Inaddition, the sensing region of the chip is usually covered by glass orother transparent material so that the sensing region is not exposed.However, when the optical sensor package module is implemented in afingerprint identification device, the identification accuracy may beimpacted because the finger cannot directly touch the sensing region.

Furthermore, the sensing region is covered by the transparent materialwhich would increase the thickness of the optical sensor package module,which may not benefit the integration of the optical sensor packagemodule with the portable electronic device.

SUMMARY OF THE INVENTION

The object of the instant disclosure is to provide a sensor chip packageand a manufacturing method thereof. In the sensor chip package, theactive region of the sensor chip is exposed without being covered by anyglass or the other transparent material so that the sensor chip packagecan be implemented in many kinds of sensing devices.

In order to achieve the aforementioned objects, according to anembodiment of the instant disclosure, a manufacturing method of thesensor chip package structure is provided. The manufacturing methodincludes the following steps. A wafer including a plurality of sensorchips is provided, and each sensor chip has an active region and definesa pre-thinned region thereon. Each pre-thinned region is located at oneside of the active region and covers a boundary line of each sensorchip. The pre-thinned region of each of the sensor chips is etched toform a concave portion located at one side of the active region. Aredistribution layer is formed on the wafer. Subsequently, a cuttingstep is performed on the wafer so that the sensor chips are separatedfrom one another, and each separated sensor chip has a wiring layerextending from the active region along a sidewall surface to a bottomsurface of the concave portion. The separated sensor chips arerespectively mounted on a plurality of substrates, and the active regionof each sensor chip is electrically connected to the substrate throughthe wiring layer.

To sum up, by the manufacturing method of the sensor chip packagestructure in accordance with the instant disclosure, the active regionof the sensor chip package structure can be exposed to the externalenvironment to be touched by an object, such as a finger. In addition,the chip body of the sensor chip includes at least one concave portiondepressed from the top surface thereof so that the light-emittingelement can be accommodated in the concave portion, thereby shorteningthe distance between the light-emitting element and the active region.

In order to further the understanding regarding the instant disclosure,the following embodiments are provided along with illustrations tofacilitate the disclosure of the instant disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a top view of a sensor chip package structure inaccordance with an embodiment of the instant disclosure;

FIG. 1B shows a sectional view taken along line IB-IB of FIG. 1A;

FIG. 2 shows a sectional view of the sensor chip package structure inaccordance with another embodiment of the instant disclosure;

FIG. 3A shows a top view of a sensor chip package structure inaccordance with another embodiment of the instant disclosure;

FIG. 3B shows a sectional view taken along line IIIB-IIIB of FIG. 3A;

FIG. 4 shows a flowchart of a manufacturing method of the sensor chippackage structure in accordance with another embodiment of the instantdisclosure;

FIG. 5 shows a top view of a wafer in step S100 of FIG. 4 in accordancewith another embodiment of the instant disclosure;

FIG. 5A shows an enlarged view of region A shown in FIG. 5;

FIG. 6A shows a top view of one of the sensor chips in step S101 of FIG.4 in accordance with an embodiment of the instant disclosure;

FIG. 6B shows a sectional view of the sensor chip shown in FIG. 6A;

FIG. 6C shows a top view of one of the sensor chips in step S101 of FIG.4 in accordance with another embodiment of the instant disclosure;

FIG. 7A shows a top view of one of the sensor chips in step S102 of FIG.4 in accordance with an embodiment of the instant disclosure;

FIG. 7B shows a sectional view of the sensor chip shown in FIG. 7A;

FIG. 8A shows a top view of one of the sensor chips in step S103 of FIG.4 in accordance with an embodiment of the instant disclosure;

FIG. 8B shows a sectional view of the sensor chip shown in FIG. 8A;

FIG. 9A shows a top view of one of the sensor chips in step S105 of FIG.4 in accordance with an embodiment of the instant disclosure;

FIG. 9B shows a sectional view of the sensor chip shown in FIG. 9A;

FIG. 10A shows a top view of one of the sensor chips in step S106 ofFIG. 4 in accordance with an embodiment of the instant disclosure;

FIG. 10B shows a sectional view of the sensor chip shown in FIG. 10A;

FIG. 11A shows a top view of one of the sensor chips in a step of themanufacturing method in accordance with another embodiment of theinstant disclosure;

FIG. 11B shows a sectional view of the sensor chip shown in FIG. 11A;

FIG. 12A shows a top view of one of sensor chips in a step of themanufacturing method in accordance with another embodiment of theinstant disclosure;

FIG. 12B shows a sectional view of the sensor chip shown in FIG. 12A;

FIG. 13A shows a top view of one of sensor chips in a step of themanufacturing method in accordance with another embodiment of theinstant disclosure;

FIG. 13B shows a sectional view of the sensor chip shown in FIG. 13A;

FIG. 14A shows a top view of an optical sensor module in accordance withan embodiment of the instant disclosure;

FIG. 14B shows a sectional view of the optical sensor module shown FIG.14A;

FIG. 15 shows a top view of an optical sensor module in accordance withanother embodiment of the instant disclosure;

FIG. 16A shows a top view of an optical sensor module in accordance withanother embodiment of the instant disclosure;

FIG. 16B shows a sectional view of the optical sensor module shown FIG.16A;

FIG. 17A shows a top view of an optical sensor module in accordance withan embodiment of the instant disclosure; and

FIG. 17B shows a sectional view of the optical sensor module shown FIG.17A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The aforementioned illustrations and following detailed descriptions areexemplary for the purpose of further explaining the scope of the instantdisclosure. Other objectives and advantages related to the instantdisclosure will be illustrated in the subsequent descriptions andappended drawings. In reference to the disclosure herein, for purposesof convenience and clarity only, directional terms, such as, top,bottom, left, right, up, down, over, above, below, beneath, rear, front,distal, and proximal are used with respect to the accompanying drawings.Such directional terms should not be construed to limit the scope of theinvention in any manner. In addition, the same reference numerals aregiven to the same or similar components.

Please refer to FIG. 1A and FIG. 1B. FIG. 1A shows a top view of asensor chip package structure in accordance with an embodiment of theinstant disclosure, and FIG. 1B shows a sectional view taken along lineIB-IB of FIG. 1A.

The sensor chip package structure provided in the embodiment of theinstant disclosure can be implemented in different sensing devices, suchas a fingerprint identification device, a sweat duct identificationdevice, an oximeter detector, a heartbeat sensor, an ambient lightsensor, or a proximity sensor. In the embodiment of the instantdisclosure, the sensor chip package structure 1 includes a substrate 10,a sensor chip 11, and a wiring layer 12.

The substrate 10 can be a metal plate, an insulating plate, or acomposite plate, in which the composite plate may be a printed circuitboard (PCB) or a flexible printed circuit (FPC). In the instantembodiment, the substrate 10 is a printed circuit board, the substrate10 has a plurality of traces (not shown in FIG. 1) embedded therein anda plurality of pads 100 disposed thereon, in which the pads 100 can bearranged according to the position of the sensor chip 11.

Additionally, in the embodiment shown in FIG. 1A, the top view of thesubstrate 10 has a basic rectangular shape, but the shape of thesubstrate 10 is not limited to the example provided herein. In anotherembodiment, the substrate 10 may have another geometric shape, such ascircular shape, elliptical shape, square shape, or triangular shape.

The sensor chip 11 is mounted on the substrate 10 and electricallyconnected to one of the pads 100 disposed on the substrate 10 through atleast one bonding wire 13. Specifically, the sensor chip 11 has a topsurface 11 a and a lower surface 11 b opposite to the top surface 11 a.The sensor chip 11 includes an active region 112 and a wiring region 113surrounding the active region 112, in which the active region and thewiring region are defined on the top surface 11 a. A control circuit,which is electrically connected to the active region 112, has been laidout in the wiring region 113 to receive the signal detected by theactive region 112.

Notably, the sensor chip 11 has at least one concave portion 115depressed from the top surface 11 a, and the concave portion 115 islocated at one side of the active region 112 and extends transverselythrough a side surface of the sensor chip 11.

Please refer to FIG. 1B. The concave portion 115 has a sidewall surface115 s and a bottom surface 115 b. The sidewall surface 115 s isconnected between the top surface 11 a and the bottom surface 115 b. Inone embodiment, the sidewall surface 115 s is an inclined surface, whichis inclined relative to the bottom surface 115 b. Specifically, thesidewall surface 115 s and the top surface 11 a form an angle θ rangingfrom 110 to 140 degree. In addition, a depth H1 of the concave portion115 is less than a height H2 of the sensor chip 11. The height H2 of thesensor chip 11 means the perpendicular distance between the top surface11 a and the lower surface 11 b. Furthermore, the depth H1 of theconcave portion 115 ranges from 100 to 400 μm.

That is to say, the sensor chip 11 includes a base portion 110 and aprotruding portion 111 protruding from an upper surface of the baseportion 110. The previously mentioned concave portion 115 is defined bythe protruding portion 111 and the base portion 110. Accordingly, thearea of a top-view figuration of the protruding portion 111 is smallerthan that of the base portion 110, and the upper surface of the baseportion 110 is the bottom surface 115 b of the concave portion 115.

In the embodiment shown in FIGS. 1A and 1B, the sensor chip 11 includestwo concave portions 115, which are respectively located at two oppositesides of the active region 112. However, the number and the location ofthe concave portion 115 can be determined according to the wiring layoutdesign, and are not limited to the example provided herein. For example,two concave portions 115 can be located at two adjacent sides of theactive region 112. In another embodiment, the sensor chip 11 can haveonly one or more than two concave portions 115.

Please refer to FIG. 1A and FIG. 1B. The wiring layer 12 is disposed onthe sensor chip 11 and electrically connected to the active region 112.Specifically, the wiring layer 12 is laid on the top surface 11 a of thesensor chip 11, the sidewall surface 115 s and the bottom surface 115 bof the concave portion 115. Furthermore, the wiring layer 12 iselectrically connected to the active region 112 through the controlcircuit arranged in the wiring region 113.

In one embodiment, the wiring layer 12 includes at least one firstcontact pad 121, at least one second contact pad 123 and a wire 122connected between the first and second contact pads 121, 123. The numberof the first and second contact pads 121, 123 and wire 122 can beadjusted according to practical demands of the sensor chips and is notintended to limit the instant disclosure.

It is worth noting that the first contact pad 121 is disposed on the topsurface 11 a of the sensor chip 11 and electrically connected to thecontrol circuit arranged in the wiring region 113. The second contactpad 123 is disposed on the bottom surface 115 b of the concave portion115, and at least a portion of the wire 122 extends from the firstcontact pad 121 disposed on the top surface 11 a along the sidewallsurface 115 s to connect to the second contact pad 123. The secondcontact pad 123 is electrically connected to the pad 100 through thebonding wire 13. As such, the active region 112 of the sensor chip 11can be electrically connected to the traces embedded in the substrate10.

That is, the sidewall surface 115 s and the bottom surface 115 b of theconcave portion 115 can serve as a layout region, so that the activeregion 112 can be electrically connected to the substrate 10 through thewiring layer 12 disposed on the sidewall surface 115 s and the bottomsurface 115 b of the concave portion 115 and the bonding wire 13.

Please refer to FIG. 2. FIG. 2 shows a sectional view of the sensor chippackage structure in accordance with another embodiment of the instantdisclosure. The same reference numerals are given to the same componentsor to components corresponding to those in FIG. 1B, and descriptions ofthe common portions are omitted.

In the instant embodiment, the sensor chip package structure 2 furtherincludes a light-emitting element 14 accommodated in the concave portion115. Specifically, the light-emitting element 14 is disposed on thebottom surface 115 b of the concave portion 115. The light-emittingelement 14 has a thickness less than the depth of the concave portion115.

The light-emitting element 14 is used to project a light beam on anobject to be tested. Thereafter, the active region 112 of the sensorchip 11 receives the reflected light beam reflected off the object toform an image of the object and for identification. The light-emittingelement 14 can be an LED, a laser source, or an infrared light source toprovide a monochromatic light or a polychromatic light.

In the instant embodiment, the light-emitting element 14 is an LED, andthe ground terminal and voltage input terminal of the LED arerespectively located at a bottom portion and a top portion of the LED.Accordingly, when the light-emitting element 14 is arranged in theconcave portion 115, the light-emitting element 14 can be disposed onone of the second contact pad 123 which is grounded, so that the groundterminal located at the bottom portion of the light-emitting element 14can be directly grounded.

In addition, in the instant embodiment, the substrate 10 includes aswitching control circuit, and the voltage input terminal located at thetop portion of the light-emitting element 14 can be electricallyconnected to the switching control circuit through the pad 100 and oneof the bonding wires 13 connecting to the pad 100. As such, theswitching control circuit can control the turn on and turn off of thelight-emitting element 14.

In another embodiment, both of the ground terminal and the voltage inputterminal are disposed on a top portion of the light-emitting element 14.In this case, the light-emitting element 14 does not have to be disposedon the second contact pad 123. That is, the light-emitting element 14can be disposed on a region of the bottom surface 115 b of the concaveportion 115 and not covered by the wiring layer 12. Furthermore, theground terminal and the voltage input terminal of the light-emittingelement 14 can be respectively electrically connected to two differentpads 100 respectively through two bonding wires 13, in which one of thepads 100 is grounded, and the other one is electrically connected to theswitching control circuit.

It is worth noting that in the prior art sensor chip package, both thelight source and the chip are directly mounted on the substrate, and thedistance between the light source and the sensing region of the chipcannot be further shortened because of the structural limitation of thechip.

In the instant embodiment, the light-emitting element 14 can be directlyformed on the sensor chip 11 by forming the concave portion 115 on thetop surface 11 a of the sensor chip 11. As such, the horizontal distancebetween the light-emitting element 14 and the active region 112 can beshortened so as to increase the image identification accuracy. Inaddition, compared to the prior art sensor chip package, the whole sizeof the sensor chip package structures provided by the instant disclosurecan be further minimized.

In one embodiment, the sensor chip package structure 2 can include atleast two light-emitting elements 14 for emitting two light beams ofdifferent colors and can be implemented in the oximeter detector. Underthese circumstances, the sensor chip 11 can have at least two concaveportions 115 to respectively accommodate these light-emitting elements14. That is, compared to the prior art sensor chip package, the wholesize of the sensor chip package structure 2 can be maintained at apredetermined level, instead of being increased significantly with theincreasing number of the light-emitting elements 14.

Subsequently, please refer to FIG. 3A and FIG. 3B. FIG. 3A shows a topview of a sensor chip package structure in accordance with anotherembodiment of the instant disclosure, and FIG. 3B shows a sectional viewtaken along line IIIB-IIIB of FIG. 3A. In the sensor chip packagestructure 3 of this embodiment, elements similar to those shown in FIG.2 are denoted by similar reference numerals, and redundant descriptionis omitted.

In the instant embodiment, the sensor chip package structure 3 of theinstant embodiment further includes a dam 15 and a molding compound 16.

Please refer to FIG. 3A. The dam 15 is disposed on the top surface 11 aof the sensor chip 11 and surrounds the active region 112 to define anenclosed opening, which can prevent the active region 112 from beingcovered by the molding compound 16 during the formation of the moldingcompound 16. The functions of the dam 15 will be explained together withthe manufacturing method of the sensor chip package structure in thefollowing description and are omitted herein.

In addition, in the instant embodiment, the dam 15 and a portion of thewiring layer 12 disposed on the top surface 11 a of the sensor chip 11partially overlap with each other in a thickness direction of the sensorchip 11. As shown in FIG. 3B, the dam 15 is stacked on the wiring layer12 (the first contact pad 121) to protect the wiring layer 12 fromoxidation or damage. In one embodiment, the dam 15 has a height rangingfrom 2 to 50 μm, and a width (W) ranging from 5 to 100 μm.

However, as long as the dam 15 can prevent the molding compound 16 fromcovering the active region 112, the relative positions between the dam15 and the wiring layer 12 are not limited. In another embodiment, aportion of the wiring layer 12 can be stacked on the dam 15, or the dam15 is directly disposed on the top surface 11 a of the sensor chip 11without overlapping with the wiring layer 12. Furthermore, the dam 15can be made of photo-imageable material, such as photoresist materialfor use in lithography process or the other insulating material.

The molding compound 16 covers the substrate 10, a portion of the sensorchip 11, and the wiring layer 12. Notably, the molding compound 16 has atop face 160 that is coplanar with or lower than an end face of the dam15. That is, the active region 112 of the sensor chip 11 would beexposed to the external environment through the enclosed opening definedby the dam 15 rather than covered by the molding compound 16, to sensoran object to be tested.

In the instant embodiment, the molding compound 16 can be made of amaterial transparent to the light beam emitted by the light-emittingelement 14, so that the light beam can be projected on the object to betested. For example, when the light beam is visible light, the moldingcompound 16 can be made of a material transparent to the visible light.In another embodiment, when the light beam is infrared light, themolding compound 16 can be made of a material transparent to theinfrared light.

It is worth noting that the sensor chip package structure 1 shown inFIGS. 1A and 1B also can include the dam 15 and the molding compound 16.When the sensor chip package structure 1 does not include thelight-emitting element 14, the material for forming the molding compound16 can be selected from opaque or transparent materials and is notlimited to the transparent material.

In an embodiment of the instant disclosure, a manufacturing method ofthe sensor chip package structure is provided. Please refer to FIG. 4,which shows a flowchart of a manufacturing method of the sensor chippackage structure in accordance with another embodiment of the instantdisclosure.

In step S100, a wafer is provided. The wafer includes a plurality ofsensor chips, and each sensor chip includes an active region and definesa pre-thinned region thereon. The pre-thinned region is positioned atone side of the active region and covers a boundary line of the sensorchip.

Please refer to FIGS. 5 and 5A. FIG. 5 shows a top view of a wafer instep S100 of FIG. 4 in accordance with another embodiment of the instantdisclosure and FIG. 5A shows an enlarged view of region A shown in FIG.5.

The wafer S1 is usually made of silicon, or the other semiconductormaterials, such as gallium arsenide, gallium nitride, or siliconcarbide. In the instant embodiment, the fabrication process of deviceshas been performed on the wafer S1 so that the wafer S1 has a pluralityof the sensor chips 11, and each sensor chip 11 includes an activeregion 112 and a wiring region 113 surrounding the active region 112,and at least one pre-thinned region 115′ (two pre-thinned regions 115′shown in FIG. 5).

Furthermore, a control circuit has been formed in the wiring region 113,and each pre-thinned region 115′ is positioned at one side of the activeregion 112. The coverage of each pre-thinned region 115′ extends to oneof boundary lines of the sensor chip 11.

Please refer to FIG. 4. Subsequently, in step S101, the pre-thinnedregion of each sensor chip is etched to form a concave portionpositioned at one side of the active region 112 of each sensor chip 11.

Please refer to FIGS. 6A and 6B. FIG. 6A shows a top view of one ofsensor chips in step S101 of FIG. 4 in accordance with an embodiment ofthe instant disclosure. FIG. 6B shows a sectional view of the sensorchip shown in FIG. 6A.

As shown in FIG. 6B, after the pre-thinned regions 115′ are etched, theconcave portions 115 depressed from the top surface 11 a are formed. Inaddition, each concave portion 115 has a sidewall surface 115 s and abottom surface 115 b, and the sidewall surface 115 s connected betweenthe top surface 11 a and the bottom surface 115 b is an inclinedsurface. In the instant embodiment, one of the concave portions 115 hasa depth ranging from 100 to 400 μm. The formation of the concave portion115 at the pre-thinned region 115′ can be carried out by performing awafer-level etching process, which may include the well-known steps ofphotoresist coating, exposure, development, etching and photoresistremoval, and so on.

That is to say, after the abovementioned etching step, each sensor chip11 includes a base portion 110 and a protruding portion 111 protrudingfrom an upper surface of the base portion 110. The active region 112 andwiring region 113 is positioned at the top surface (i.e., top surface 11a) of the protruding portion 111. In addition, a portion of the uppersurface of the base portion 110 not covered by the protruding portion111 is the bottom surface 115 b of the concave portion 115. Theprotruding portion 111 has at least one inwardly sidewall surface, thatis, the sidewall surface 115 s of the concave portion 115. Furthermore,the protruding portion 111 has a height relative to the upper surface ofthe base portion 110 that is equal to the depth of the concave portion115.

In the embodiment shown in FIG. 6A, each sensor chip 11 includes twoconcave portions 115 respectively formed at two opposite sides of theactive region 112. In another embodiment as shown in FIG. 6C, eachsensor chip 11′ can include four concave portions 115 according topractical demands, and the four concave portions 115 respectively extendtransversely through four boundary lines of the corresponding sensorchip 11′. In another embodiment, the sensor chip 11 can have only oneconcave portion 115, and the number of the concave portion 115 is notlimited to the example provided herein.

Please refer to FIG. 4. In step S102, a redistribution layer is formedon the wafer. Please refer to FIG. 7A and FIG. 7B. FIG. 7A shows a topview of one of the sensor chips in step S102 of FIG. 4 in accordancewith an embodiment of the instant disclosure, and FIG. 7B shows asectional view of the sensor chip shown in FIG. 7A.

As shown in FIGS. 7A and 7B, the redistribution layer 12′ is formed onthe top surface 11 a of each sensor chip 11, the sidewall surface 115 sand the bottom surface 115 b of the concave portion 115. Theredistribution layer 12′ includes a plurality of first contact pads 121disposed on the top surface 11 a, a plurality of second contact pads 123disposed on the bottom surface 115 b of the concave portion 115, and aplurality of wires 122. Each wire 122 is connected between each firstcontact pad 121 and each second contact pad 123.

As shown in FIG. 7B, the first contact pad 121 is disposed on the topsurface 11 a of the sensor chip 11 and electrically connected to thecontrol circuit formed in the wiring region 113. The second contact pad123 is disposed on the bottom surface 115 b of the concave portion 115,and at least a portion of the wire 122 extends from the first contactpad 121 disposed on the top surface 11 a along the sidewall surface 115s of the concave portion 115 to the second contact pad 123 disposed onthe bottom surface 115 b.

The step of forming the redistribution layer 12′ can be carried out byperforming a lithography process. It is worth noting that thelithography process includes the steps of exposure and development, andthe sidewall surface 115 s of the concave portion 115 is an inclinedplane, which can ensure the sidewall surface 115 s can be completelyimpinged upon during the steps of exposure and development. As such, thewire 122 can be formed without breaks to ensure the electricalconnection between the first and second contact pads 121, 123 can beestablished.

Additionally, in the following process, the active region 112 can beelectrically connected to the traces or circuit of the substrate 10through the plurality of the second contact pads 123 disposed on thebottom surface 115 b of the concave portion 115. Accordingly, theredistribution layer 12′ can be made of the metal or alloy which iseasily bonded with the pads 100 disposed on the substrate 10, such asnickel, tin, silver or alloys thereof.

Please refer to FIG. 4. Subsequently, in step S103, a dam is formed oneach sensor chip, in which the dam surrounds the active region anddefines an enclosed opening.

Please refer to FIG. 8A and FIG. 8B. FIG. 8A shows a top view of one ofthe sensor chips in step S103 of FIG. 4 in accordance with an embodimentof the instant disclosure, and FIG. 8B shows a sectional view of thesensor chip shown in FIG. 8A.

As shown in FIG. 8A and FIG. 8B, the dam 15 is formed on top surface 11a of each sensor chip 11 and surrounds the active region 112. In oneembodiment, the dam 15 is made of photo-imageable material. Therefore,the dam 15 can be formed by the steps of photoresist coating, exposureand development. The dam 15 has a height ranging from 2 to 50 μm, and awidth (W) ranging from 5 to 100 μm.

In the instant embodiment, the dam 15 is stacked on a portion of theredistribution layer 12′. Accordingly, the step of forming the dam 15 isperformed after the step of forming the redistribution layer 12′. Inanother embodiment, the sequence of the steps of forming the dam 15 andthe redistribution layer 12′ is not intended to limit the instantdisclosure.

Subsequently, please refer to FIG. 4, which shows in step S104, acutting process is performed on the wafer to form a plurality ofseparated sensor chips, in which at least a portion of a wiring layer isdisposed on the separated sensor chip and extends from the active regionalong the sidewall surface to the bottom surface of the concave portion.

Please refer to FIG. 8A and FIG. 8B. When the cutting process isperformed on the wafer S1 (as shown in FIG. 5), the wafer S1 is cutalong a plurality of cutting lines (L) intersecting with each other toseparate the sensor chips 11 from one another. Notably, after thecutting process, the redistribution layer 12′ is cut so as to form aplurality of wiring layers 12 respectively formed on the separatedsensor chips 11. Similar to the redistribution layer 12′, each wiringlayer 12 may include a plurality of first contact pads 121, a pluralityof second contact pads 123 and a plurality of wires 122, and each ofwire 122 is connected between the corresponding first and second contactpads 121, 123. The position and functions of the wiring layer 12 areomitted herein.

Please refer to FIG. 4. Subsequently, in step S105, a plurality ofseparated sensor chips are respectively disposed on a plurality ofsubstrate, and the active region of one of the sensor chips iselectrically connected to the substrate. Please refer to FIG. 9A andFIG. 9B. FIG. 9A shows a top view of one of sensor chips in step S105 ofFIG. 4 in accordance with an embodiment of the instant disclosure, andFIG. 9B shows a sectional view of the sensor chip shown in FIG. 9A.

Specifically, as shown in FIG. 9A, a plurality of traces and pads 100have been configured on the substrate 10, and the separated sensor chip11 is mounted on a predetermined position of the substrate 10.

In one embodiment, the second contact pads 123 are respectivelyelectrically connected to the corresponding pads 100 through the bondingwires 13 by performing a wire bonding process. As mentioned above, thewiring layer 12 is electrically connected to the control circuit formedin the wiring region 113 so that the pads 100 on the substrate 10 areelectrically connected to the active region 112.

Please refer to FIG. 4. In step S106, a molding compound is formed toencapsulate the substrate, the sensor chip and the wiring layer, inwhich the molding compound exposes the active region.

In one embodiment, the molding compound is formed by performing atransfer molding process. Notably, during the transfer molding process,the substrate 10 and the sensor chip 11 are placed commonly in the mold,and the epoxy molding compound is injected into the mold. The process offorming the molding compound is formed after the epoxy molding compoundis cured.

Please refer to FIG. 10A and FIG. 10B. FIG. 10A shows a top view of oneof sensor chips in step S106 of FIG. 4 in accordance with an embodimentof the instant disclosure, and FIG. 10B shows a sectional view of thesensor chip shown in FIG. 10A.

Notably, when the mold is injected into the epoxy molding compound, thedam 15 formed in step S103 can prevent the epoxy molding compound fromflowing and covering the active region 112. Accordingly, a top face 160of the molding compound 16 would be coplanar with (as shown in FIG. 10B)or lower than an end face of the dam 15. Therefore, the active region112 of the sensor chip 11 would be exposed to the external environmentthrough the enclosed opening defined by the dam 15 rather than coveredby the molding compound 16.

Furthermore, in the instant embodiment, because the bonding wire 13 isdirectly connected to the second contact pad 123 positioned at thebottom surface 115 b of the concave portion 115 and electricallyconnected to the active region 112 through the wire 122, a top point ofthe bonding wire 13 would be lower than a level where the top surface 11a of the sensor chip 11 is located. Additionally, since the top face 160of the molding compound 16 is coplanar with the top end of the dam 15,the molding compound 16 can encapsulate the bonding wire 13.

In another embodiment, the sensor chip 11 and the substrate 10 can bepackaged by other means. For example, during injecting into the epoxymolding compound, a cover having an opening can be provided to cover thesensor chip 11 and the substrate 10 and make the active region 112 beexposed through the opening to achieve the same results. Under theseconditions, the step S103 can be omitted, i.e., the dam 15 isalternately formed on the top surface 11 a of the sensor chip 11.

In another embodiment, after the step S102, the manufacturing method ofthe sensor chip package structure can further include arranging alight-emitting element in the concave portion.

Specifically, please refer to FIG. 11A and FIG. 11B, in which FIG. 11Ashows a top view of one of sensor chips in a step of the manufacturingmethod in accordance with another embodiment of the instant disclosure,and FIG. 11B shows a sectional view of the sensor chip shown in FIG.11A.

In the embodiment shown in FIGS. 11A and 11B, the light-emitting element14 is disposed on the bottom surface 115 b of the concave portion 115.In addition, the light-emitting element 14 has a thickness less than adepth of the concave portion. Furthermore, when the light-emittingelement 14 has a ground terminal disposed on the bottom, thelight-emitting element 14 can be stacked on one of the second contactpads 123 electrically connected to ground. That is to say, the secondcontact pads 123 where the light-emitting element 14 is stacked is aground pad, and the wire 122 and the first contact pad 121 which areconnected to the ground pad are mated with each other to form agrounding circuit.

In another embodiment, when both the ground terminal and the voltageinput terminal of the light-emitting element 14 are disposed on a topportion of the light-emitting element 14, the light-emitting element 14can be disposed on the bottom surface 115 b of the concave portion 115instead of stacked on the second contact pad 123.

After the light-emitting element 14 is arranged in the concave portion115, a cutting process is performed on the wafer to form a plurality ofseparated sensor chips 11. Subsequently, please refer to FIGS. 12A and12B. FIG. 12A shows a top view of one of sensor chips in a step of themanufacturing method in accordance with another embodiment of theinstant disclosure, and FIG. 12B shows a sectional view of the sensorchip shown in FIG. 12A.

As illustrated in FIG. 12A, the sensor chip 11 and the light-emittingelement 14 disposed thereon are disposed on the substrate 10. During thestep of disposing the sensor chip 11 on the substrate 10, themanufacturing method further includes forming at least one bonding wire13 so that the light-emitting element 14 is electrically connected tothe substrate 10. As shown in FIG. 12B, the light-emitting element 14 isconnected to the pad 100 of the substrate 10 through the bonding wire 13such that an electrical connection between the light-emitting element 14and a control circuit (ex: switching control circuit) can beestablished.

Subsequently, please refer to FIGS. 13A and 13B, which respectivelyshows a top view of one of sensor chips in a step of the manufacturingmethod in accordance with another embodiment of the instant disclosure,and a sectional view of the sensor chip shown in FIG. 13A.

Similar to the step S106 shown in FIG. 4, the molding compound 16 isformed to encapsulate the substrate 10, the sensor chip 11, thelight-emitting element 14, and the wiring layer 12, in which the moldingcompound exposes the active region 112 of the sensor chip 11.

Please refer to FIGS. 14A and 14B, which respectively shows a top viewof an optical sensor module in accordance with another embodiment of theinstant disclosure, and a sectional view of the sensor chip shown inFIG. 14A.

The optical sensor module 4 includes a substrate 40, a sensor chip 41,and a passive chip 42. The substrate 40 can be a metal plate, aninsulating plate, or a composite plate, in which the composite plate maybe a printed circuit board (PCB) or a flexible printed circuit (FPC). Inthe instant embodiment, the substrate 40 is a printed circuit board, thesubstrate 40 has a plurality of traces (not shown in FIG. 14A) embeddedtherein and a plurality of pads 400 disposed thereon, in which the pads400 can be arranged according to the position of the sensor chip 41.

As shown in FIG. 14A and FIG. 14B, the sensor chip 41 is disposed on thesubstrate 40. The sensor chip 41 includes a chip body 410 and amulti-functional structure 416 disposed on the chip body 410.

The chip body 410 has a top surface 410 a and a lower surface 410 bopposite to the top surface 410 a. In addition, the chip body 410includes an active region 412 and a wiring region 413. The active region412 is located at a top side of the chip body 410 and exposed at the topsurface 41 a. The wiring region 413 located at the top side of the chipbody 410 surrounds the active region 412. A control circuit, which iselectrically connected to the active region 412, has been laid out inthe wiring region 413 to receive the signal detected by the activeregion 412.

In the instant embodiment, the sensor chip 41 is electrically connectedto the pads 400 of the substrate 40 by flip-chip bonding. That is tosay, the sensor chip 41 includes a plurality of internal conductiveplugs 411 penetrating through the chip body 410 and a plurality offlip-chip pads 414 respectively corresponding to the internal conductiveplugs 411 and mounted at the lower side of the chip body 410. The activeregion 412 is electrically connected to the substrate 40 through theinternal conductive plugs 411 and the corresponding flip-chip pads 414.In one embodiment, the internal conductive plugs 411 can be formed bythrough silicon via process.

Furthermore, the chip body 410 has at least one recess portion 415depressed from the top surface 410 a thereof. In the instant embodiment,the recess portion 415 has a sidewall surface 415 s and a bottom surface415 b, and the sidewall surface 415 s is an inclined surface, which isconnected between the top surface 410 a and the bottom surface 415 b. Inthe instant embodiment, one of the recess portions 415 has a depth Dless than a thickness T of the chip body 410.

Additionally, the recess portion 415 is positioned at one side of theactive region 412 and spaced from all of side surfaces of the chip body410. Specifically, the recess portion 415 is enclosed within the chipbody 410. Furthermore, the recess portion 415 is spaced from the activeregion 412 by a distance ranging from 0.5 cm to 1 cm. In anotherembodiment, the recess portion 415 extends elongatingly toward twoopposite edges of the chip body 410 or the recess portion 415 extendstoward one edge of the chip body 410 and opens outwardly.

In the instant embodiment, the recess portion 415 is configured toaccommodate the passive chip 42 so that the distance between the activeregion 12 and the passive chip 42 can be reduced. Additionally, thedepth D of the recess portion 415 is greater than a thickness of thepassive chip 42. That is to say, when the passive chip 42 isaccommodated in the recess portion 415, a top end of the passive chip 42does not protrude from the top surface 410 a of the chip body 410. Assuch, even if the sensor chip 41 is equipped with the passive chip 42,the size of the sensor chip 41 does not increase due to the passiveelement 42. In other words, by placing the passive chip 42 in the recessportion 415, the optical sensor module 4 has a smaller size.

The passive chip 42 can be a light-emitting component for emitting lightprojecting on an object to be tested. The active region 412 receives thereflected light reflected off the object to form an image of the objectand for identification. The light-emitting component can be an LED or alaser diode for generating a monochromatic light or a polychromaticlight, such as visible light, UV light, or infrared light.

As shown in FIG. 14B, the multi-functional structure 416 is disposed onan inner surface of the recess portion 415 for electrically connectingthe passive chip 42 to the substrate 40.

Specifically, the multi-function structure 416 can include aredistribution layer 4160 disposed on the top surface 410 a of the chipbody 410, the sidewall surface 415 s and the bottom surface 415 b of therecess portion 415. In the instant embodiment, the redistribution layer4160 includes a first conductive portion 4161 and a second conductiveportion 4162, which are insulated from each other. In one embodiment,the first and second conductive portions 4161, 4162 are spaced by a gapto be insulated from each other, as shown in FIG. 14A. However, inanother embodiment, the first and second conductive portions 4161, 4162can be electrically insulated from each other by disposing an insulatinglayer therebetween. Accordingly, as long as the first and secondconductive portions 4161, 4162 can be electrically insulated from eachother, the instant disclosure is not so restricted.

In the embodiment shown in FIGS. 14A and 14B, the first conductiveportion 4161 includes a first contact pad 4161 a disposed on the topsurface 410 a and a first wiring layer 4161 b extending from the firstcontact pad 4161 a to the bottom surface 415 b along one part of thesidewall surface 415 a. Moreover, the first contact pad 4161 a can beelectrically connected to one of the pads 400 of the substrate 40through the corresponding internal conductive plug 411.

Similarly, the second conductive portion 4162 includes a second contactpad 4162 a disposed on the top surface 410 a of the chip body 410 and asecond wiring layer 4162 b extending from the second contact pad 4162 ato the bottom surface 415 b along the other part of the sidewall surface415 a. The second contact pad 4162 a can be electrically connected toanother one of the pads 400 of the substrate 40 through thecorresponding internal conductive plug 411.

In the instant embodiment, the passive chip 42 is electrically connectedto the substrate 40 by flip-chip bonding. That is to say, the firstterminal 421 and the second terminal 422 positioned at the bottom sideof the passive chip 42 can be electrically connected to the substrate400 without any bonding wire.

Specifically, when the passive chip 42 is disposed on the bottom surface415 b of the recess portion 415, the first terminal 421 and the secondterminal 422, which are located at the bottom side of the passive chip42, are respectively in contact with and bonded to a first wiring layer4161 a and the second wiring layer 4162 b. Additionally, the substrate40 includes a switching control circuit for controlling the passive chip42, and the first terminal 421 and the second terminal 422 can beelectrically connected to the switching control circuit through theinternal conductive plugs 411, the flip-chip pads 414 and the pads 400.

In one embodiment, when the passive chip 42 is the light-emittingcomponent for emitting infrared light, the redistribution layer 416 ofthe instant embodiment can be served as a shielding layer for preventingthe active region 412 from receiving the light emitted by thelight-emitting component. In other words, the redistribution layer 416is not only used for electrically connecting the passive chip 42 to thesubstrate 40, but also for preventing the active region 412 fromreceiving light emitted by the passive chip 42.

Specifically, since silicon (the material of the chip body 410) ispartially transparent to infrared light, the infrared light emitted bythe light-emitting component may pass through the chip body 410 and theninterfere with the normal signal received by the active region 412.Thus, the infrared light received by the active region 412 may result inhigher signal noise and lower image identification accuracy.Accordingly, in the instant embodiment, at least one of the first wiringlayer 4161 b and the second wiring layer 4162 b covers a portion of thesidewall surface 415 s that is closest to the active region 412 so thatthe active region 412 is isolated from the infrared light. That is, atleast one of the first wiring layer 4161 b and the second wiring layer4162 b can be located between the light-emitting component (the passivechip 42) and the active region 412 to prevent the active region 412 fromreceiving the infrared light. In this case, the first wiring layer 4161b or the second wiring layer 4162 b can be made of metal material, suchas aluminum (Al) or chromium (Cr). In another embodiment, the firstwiring layer 4161 b or the second wiring layer 4162 b can be designed toisolate the light with the wavelength falling within another range.

Furthermore, the redistribution layer 416 of the instant embodiment alsocan be served as a reflecting layer for reflecting the light emitted bythe light-emitting component. Specifically, the first wiring layer 4161b and the second wiring layer 4162 b commonly cover the sidewall surface415 s of the recess portion 415 with 80% to 90% surface area coverage.That is to say, the first wiring layer 4161 b and the second wiringlayer 4162 b commonly surround the passive chip 42. Furthermore, each ofthe first wiring layer 4161 b and the second wiring layer 4162 b is ametal layer having a reflective surface for reflecting light emittedfrom the light-emitting component. As such, the functions of the recessportion 415 and the redistribution layer 416 are similar to that of areflective cup so as to adjust the light emitting angle and increase theluminous efficacy of the light-emitting component.

Additionally, the sensor chip 41 further includes a protective material418 disposed in the recess portion 415. The protective material 418 canbe resin, such as epoxy, silicone, or the other materials. Theprotective material 418 in liquid state can be injected into the recessportion 415 until the protective material 418 completely covers thepassive chip 42. Subsequently, the protective material 418 can be curedand encapsulate the passive chip 42 to protect the passive chip 42 frommoisture. In one embodiment, when the passive chip 42 is thelight-emitting component, the protective material 418 is transparent tothe light emitted by the light-emitting component. In the instantembodiment, a top face (not labeled) of the protective material 418 canbe coplanar with or be lower than the top surface 410 a of the chip body410.

Please refer to FIG. 15. FIG. 15 shows a top view of an optical sensormodule in accordance with another embodiment of the instant disclosure.As shown in FIG. 15, the multi-function structure 416 can furtherinclude a reflective layer 4163 disposed on the sidewall surface 415 sof the recess portion 415 for reflecting light emitted by thelight-emitting component (the passive chip 42).

Specifically, in the instant embodiment, the multi-function structure416 includes the redistribution layer 4160 and a reflecting layer 4163.In the instant embodiment, the first wiring layer 4161 a of theredistribution layer 4160 only covers a portion of the sidewall surface415 s that is located between the active region 412 and the passive chip42 so as to prevent light emitted by the passive chip 42 from enteringthe active region 412. The reflecting layer 4163 covers the otherportions of sidewall surface 415 s which are not occupied by the firstwiring layer 4161 b and the second wiring layer 4162 b. The reflectinglayer 4163 of the instant embodiment is made of an insulator so that thefirst wiring layer 4161 b and the second wiring layer 4162 b areinsulated from each other. In other words, the inner surface (includingthe sidewall surface 415 s and the bottom surface 415 b) of the recessportion 415 is completely covered by the first wiring layer 4161 b, thesecond wring layer 4162 b and the reflecting layer 4163.

Please refer to FIG. 16A and FIG. 16B. FIG. 16A shows a top view of anoptical sensor module in accordance with another embodiment of theinstant disclosure. FIG. 16B shows a sectional view of the opticalsensor module shown FIG. 16A. In the instant embodiment, themulti-function structure 416 includes a shielding layer 4164 disposed onat least one portion of the sidewall surface 415 s that is closest tothe active region 412. The shielding layer 4164 can be made of thematerial that can be an insulator and substantially non-transparent tolight emitted by the light-emitting component.

Please refer to FIGS. 17A and 17B, which respectively shows a top viewof an optical sensor module in accordance with another embodiment of theinstant disclosure and a sectional view of the optical sensor moduleshown FIG. 17A.

In the instant embodiment, the first terminal 421 and the secondterminal 422 of the passive chip 42 are respectively positioned at twoopposite sides of the passive chip 42. Furthermore, the passive chip 42is electrically connected to the substrate 40 by wire bonding.

Specifically, as shown in FIG. 17B, the first terminal 421 located atthe bottom side of the passive chip 42 is directly in contact with thefirst wiring layer 4161 a, and the second terminal 422 located at thetop side of the passive chip 42 is electrically connected to the secondwiring layer 4162 b by a boning wire L1. Notably, the recess portion 415has a larger space than that in the previous embodiment shown in FIG.14A so as to provide a space for the bonding wire L1. Specifically, thebottom surface 415 b of the recess portion 415 has an area larger thanthat in the previous embodiment shown in FIG. 14A. However, the size ofthe recess portion 415 should be limited such that the structuralintegrity of the sensor chip 41 will not be compromised thereby.

It is worth noting that in the prior art optical sensor module, both thelight-emitting component and the chip are directly mounted on thesubstrate, and the distance between the light-emitting component and thesensing region of the chip cannot be further shortened due to thestructural limitation of the chip.

In the instant embodiment, the passive chip 42 (or the light-emittingcomponent) can be directly placed on the chip body 410 of the sensorchip 41 due to the formation of the recess portion 415 on the topsurface 410 a of the chip body 410. As such, the horizontal distancebetween the passive chip 42 and the active region 412 can be shortenedso as to increase the image identification accuracy. In addition, sincethe sensor chip 41 is electrically connected to the substrate 40 byflip-chip bonding, instead of wiring boding, the molding compound, whichis used in the previous embodiment shown in FIG. 3B to protect thebonding wire 13, can be omitted. As such, compared with the sensor chippackage structure of the previous embodiment, the optical sensor module4 of the instant embodiment has a smaller size.

To sum up, the sensor chip package structure and the manufacturingmethod thereof in accordance with the instant disclosure can make theactive region be exposed to the external environment to be directlytouched by an object, such as a finger. In addition, the sensor chipincludes at least one concave portion depressed from the top surface sothat the wiring layer can be disposed on the bottom surface and thesidewall surface of the concave portion to establish the electricalconnection between the active region and the substrate.

Additionally, by forming the concave portion or the recess portion inthe sensor chip, the light-emitting element or the passive chip can bedirectly disposed on the sensor chip. As such, the horizontal distancebetween the light-emitting element and the active region can beshortened, which is of benefit for improving the image identificationaccuracy. In addition, compared to the prior art sensor chip package,since the light-emitting element of the sensor chip package structureand the optical sensor module provided in the instant disclosure can bedirectly disposed on the sensor chip, the size of the sensor chippackage structure and the optical sensor module can be smaller.

The descriptions illustrated supra set forth simply the preferredembodiments of the instant disclosure; however, the characteristics ofthe instant disclosure are by no means restricted thereto. All changes,alterations, or modifications conveniently considered by those skilledin the art are deemed to be encompassed within the scope of the instantdisclosure delineated by the following claims.

What is claimed is:
 1. A manufacturing method of a sensor chip packagestructure comprising: providing a wafer including a plurality of sensorchips, wherein each sensor chip includes an active region and defines atleast a pre-thinned region thereon, and the pre-thinned region islocated at one side of the active region and covers a boundary line ofthe sensor chip; etching the pre-thinned region of each sensor chip toform a concave portion located at one side of the active region; forminga redistribution layer on the wafer; performing a cutting process on thewafer to form a plurality of separated sensor chips, wherein eachseparated sensor chip includes a wiring layer disposed thereon, and atleast a portion of the wiring layer extends from the active region alonga sidewall surface to a bottom surface of the concave portion; anddisposing each separated sensor chip on a substrate, wherein the activeregion of each separated sensor chip is electrically connected to thesubstrate.
 2. The manufacturing method of the sensor chip packagestructure according to claim 1, further comprising: forming a dam oneach sensor chip, wherein the dam surrounds the active region anddefines an enclosed opening.
 3. The manufacturing method of the sensorchip package structure according to claim 2, wherein the step of formingthe dam is performed after the step of forming the redistribution layer,and the dam is stacked on a portion of the redistribution layer.
 4. Themanufacturing method of the sensor chip package structure according toclaim 2, further comprising: forming a molding compound to encapsulatethe substrate, the separated sensor chip, and the wiring layer after thestep of disposing each separated sensor chip on the substrate.
 5. Themanufacturing method of the sensor chip package structure according toclaim 4, wherein a top face of the molding compound is coplanar with orlower than an end face of the dam.
 6. The manufacturing method of thesensor chip package structure according to claim according to claim 2,wherein the dam is made of photo-imageable material.
 7. Themanufacturing method of the sensor chip package structure according toclaim according to claim 2, wherein the dam has a height ranging from 2to 50 μm and a width ranging from 5 to 100 μm.
 8. The manufacturingmethod of the sensor chip package structure according to claim 1,further comprising: arranging a light-emitting element in the concaveportion, wherein the step of disposing each separated sensor chip on thesubstrate includes grounding the light-emitting element through thewiring layer.
 9. The manufacturing method of the sensor chip packagestructure according to claim 8, wherein the step of disposing eachseparated sensor chip on the substrate includes forming at least abonding wire so as to establish an electrical connection between thelight-emitting element and the substrate.
 10. The manufacturing methodof the sensor chip package structure according to claim according toclaim 8, wherein the light-emitting element has a thickness less than adepth of the concave portion.
 11. The manufacturing method of the sensorchip package structure according to claim according to claim 8, whereinthe step of arranging the light-emitting element is performed beforeperforming the cutting process.
 12. The manufacturing method of thesensor chip package structure according to claim according to claim 8,further comprising: forming a molding compound to encapsulate thesubstrate, the separated sensor chip, and the wiring layer, and thelight-emitting element after the step of disposing each separated sensorchip on the substrate, and the molding compound is made of a materialtransparent to a light beam emitted by the light-emitting element.